George Frederick McWilliams (10 November 1865 – 12 February 1907) was an Australian medical doctor, military surgeon, and politician.

With Mathieson Jacoby, McWilliams helped to found the state branch of the St John Ambulance, and served as the inaugural president.

[1] During the Second Boer War, McWilliams volunteered with the West Australian Mounted Infantry, serving as the contingent's chief medical officer.

[1] McWilliams entered parliament at the 1901 North Perth by-election, which had been caused by the death of Richard Speight after only a few months in office.

[3] He was buried at Karrakatta Cemetery with full military honours, with the service conducted by the Bishop of Perth, Charles Riley.